| Publications |
Here you will find a list of useful publications on wind energy.
A complete chronological list can be found at the bottom of this page (most recent last)
In my net-zero energy house, a wind turbine provides about half my power. Here is an hour-long public radio interview about my house (WJFF Catskills Public Radio) . MP3 of radio interview
Here is a slide show about how my net-zero energy house was designed. Mel Tyree's slide show and for a more detailed blow-by-blow history regarding regulatory issues and technical problems see my personal history.
Here is the Home Power Magazine article (Issue 125, June-July 2008) with the deleted paragraph reinserted HP125 and in case your version of Acrobat Reader cannot pull up the paragraph you may click on the missing paragraph.
WHY DOES MY TURBINE PRODUCE LESS kWh THAN ESTIMATED BY MY INSTALLER? Okay, I admit this is a rather biased question. But so far I have not seen a contrary example. If your turbine produces more energy then predicted by your installer please send me your data and I will add it to this site! Professor Tyree's turbine was produced 60% of what was predicted in the first year. Joe Waldowski's turbine near Edmonton, Canada, produced only about 19% (see factsheet) of what was predicted. Why? Well, of course, the predictions are only as good as the wind maps used to make the preditions and wind resources change from year to year at any given site, but the customer should be aware of these problems. The Massachusettes Technology Collaborative (MTC) provides large subsidies for the installation of small wind turbines in MA so they contracted the Cadmus Group to report on performance of the installed turbines (see report), and Fig 5 in this report is rather telling: the annual production of installed turbines has been 10% to 55% of the installer-predicted values. To be fair, I have to point out that Paul Gay sees a lot of technical problems in the Cadmus report (see critique), but regardless of the cause of the 'errors' the buyer needs to be careful in believing predictions. If predictions were based on 'good scientific principles' you might reasonably expect some predictions to be high and some low, but with an average prediction that is more or less correct when averaged over a large number of sites. So far, I have seen 21predictions that are consistently high. SO PLEASE ADD YOUR DATA SO WE HAVE A MORE BALANCED REPORT ON THE NEXT REVISION OF THIS WEB SITE. I have just completed a sensitivity analysis of the model usually used to predict annual production; click for this preliminary report
DOE NREL tested three small wind turbines and unpublished test results can be found NREL Tests one study in particular shows how the GridTek10 inverter cuts out when wind speed gets too high 33963.pdf (see Figures 6 & 7). Hence lots of power is lost at windy sites. People have been waiting for my preliminary data on energy loss on windy days due to GridTech10 inverter performance. Download report#1 and my RawData.
DOE NREL: Here is a newer study of the Skystream turbine NREL Skystream report; this turbine/inverter has a good power curve to high wind velocities. ExecutiveSummary#2
The USDA recently tested two small wind turbines for noise and power output. These test compare new versus old blade designs on Bergey wind turbines. USDA Tests; although the new SH3055 blades harvest more energy at low wind speeds the energy yield at high wind speeds drop off faster than for the old blades. Hence you would not want to use these blades at a really windy site. If you do not want to wade through a long report look at the Executive Summary #1
Stew wrote to me (9 May 08) about an inconsistency between what 'industry' says about the performance of turbine blades and what government tests at NREL actually find. So thanks to Stew I have compiled the following summary report on blades. I welcome comments to help me improve or correct this report.
Derivation of Wind Power Equation.
How to build your own turbine (not for the faint hearted) Dan Lenox's Wind Turbine
Chronological list of postings (most recent last):
R#1: Our new home with ZERO carbon footprint (a blow by blow account of how Mel Tyree built his experimental house).
R#2: NREL-Skystream-Report-39157 (power curves and more for a < 2 kW turbine).
R#3: NREL report 33963 (Bergey turbine, Safety and Function Test)
R#4: My Net Zero Engery House (Mel Tyree's slide show)
R#5: 10-steps to building your own small wind turbine.
R#6: Wind Power for Farms.
R#7: Tyree Radio Interview (1 h interview about his net zero energy house).
R#8: USDA Tests of Power And Noise in Small Wind Turbines.
R#9: Executive Summary1 regarding Bergey Turbine Blades see R#8.
R#10: Executive Summary2 regarding the SkyStream Turbine.
R#11: Raw data relevent to item R#12
R#12: An Example of Power Loss during a Windy Event (GridTek10 Inverter)
R#13: Paragraph deleted from Home Power Magazine article in R#14.
R#14: HP125_pg46_Tyree (Home Power Magazine Article about Mel Tyree's home)
R#15: Original prediction of energy production of Mel's turbine.
R#16: Original prediction of energy production of Joe Waldoski turbine.
R#17: Cadmus Group Preliminary Report of Performance of 19 turbines installed in Massachusettes.
R#18: Paul Gays Response to Cadmus Report
R#19: Engineering Study of the Performance of an Open Loop Geothermal Heat Pump.
R#20: Mel Tyree's derivation of basic equation for power from wind.
R#21: Industry Standard Model to estimate energy production from turbines (prior to R#17).
R#22: Sensitivity analysis done by Mel Tyree on R#21.
R#23: Mel Tyree's response to claims by Mike Bergey about improvements to turbine blades.
R#24: R#19 revised Engineering Study of my Open Loop Geothermal Heat Pump.
R#25: Looming Credibility Issue for the Small Wind Industry: An opinion paper by Mel Tyree relating to R#17.
R#26: NREL Report 33450.pdf giving test protocol for small wind turbines and some Bergey results.
R#27: An early improvement in cup anemometers by P. A Sheppard.
R#28: Are Wind Turbines Anemometers?: An Opinion Paper by Mel Tyree
R#29: Alfred University power curve on a Bergey in reference to R#28.
R#30: Towards an improved model of Annual Production of Energy: Part 1 Impact of Turbulence Index
R#31: Excel file with model used in R#30. Graphs and data are on top of each other so you will have to move them around to see everything.
R#32: How Wind Energy Models are developed and validated.
R#33: TIMAPE Part II How air density variations influence Yp = Annual Energy Production
R#34: TIMAPE Part III Charles Ronse model on the impact of TI= Turbulence Intensity (a better model than in R#30)
R#35: Net-Zero Energy Houses: a vision of the future. Talk given at Canadian National Solar Housing Conference, Fredericton, New Bruswick 19 Aug 2008
R#36: TIMAPE Part IV, which addresses the issue of how well the Weibull function estimates real world probability density function of wind speed. The Weibull function is an essential part of WindCad models.
R#37: Geoff Thomas's suggestion on low-cost wind energy assessment for residential turbine sites.
R#38: A few critical comments about the economics of small wind turbines in response to an article in Home Power Magazine vol 126 Page 84.
R#39: Remote Reset Project, Correcting for a design fault in the GridTek10 inverter for a 10 kW Bergery
R#40 Interim Report on Energy Loss In A GridTied Bergey 10 kW Turbine.
R#41 GridTek10 inverter raw performance data GridTek10.xls (supports R#42)
R#42 GridTek10 performance data report (efficiency and status when it overloads).
R#43. Appalachian State University power curve for a SkyStream turbine Nov 08
R#44: Cost-Benefit analysis note regarding replacing a GridTek10 inverter.
R#45: Spreadsheet connected with R#44.
R#46: Power production of a furled Bergey 10 kW turbine. Does it help to furl when it is very windy?
R#47: Second InterimReport on Energy Loss in a GridTied Bergey 10 kW Turbine.
R#48: Epistles to Michael Klemen: #1 How I measure wind speed.
R#49: DIRM model for instantaneous power prodcution from a 10 kW turbine (Epistle #2 to Michael Klemen).
R#50: Formal Response to Mike Bergey on Energy Loss in the BWC Excel-s turbine.
R#51: Accuracy and resolution in wind energy measurements: Epistle #4 to Michael Klemen
R#52: Third Interim Report on Energy Loss in a GridTied Bergey 10 kW Turbine
R#53: How the new federal tax credit on small wind turbines might work.
R#54: May 2009 report on performance of my open loop Geothermal Heat Pump
R#55: Supporting Excel sheet for Appendix 1 in R#54.
R#56: Comparing Bergey Windpower Inverters (PowerSyncII vs GridTek10)
R#57 & R#58: Raw data in support of R#56 above.
R#59: Measuring wind speed of NRG cup anemometers using AC voltage.